\begin{tikzpicture}
    \tkzDefPoints{0/0/O}
    \tkzDefPoint(270:1.5){A}
    \tkzDefLine[perpendicular=through A,normed](O,A)  \tkzGetPoint{T}
    \tkzDefPointOnLine[pos=2.0](A,T)  \tkzGetPoint{T}
    \tkzDefPointOnLine[pos=.4](A,T)  \tkzGetPoint{M}

    \tkzDrawCircle[thick](O,A)
    \tkzDrawPoint(O)
    \tkzDrawSegment(O,A)
    \tkzDrawLine[add=0 and 1](T,A)
    \tkzDrawSegment[dashed](O,M)
    \tkzLabelPoints[above](O)
    \tkzLabelPoints[below](A,M)
    \tkzLabelPoints[right](T)
\end{tikzpicture}

